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Abstract:

A fixture assembly for securing at least one side rail to a shroud tile
of a gas turbine is disclosed. The fixture assembly may include a first
support member, a second support member, a first guide block and a second
guide block. The first and second guide blocks may be formed from a
material that has the same or a similar coefficient of thermal expansion
as the material used to form at least one of the shroud tile and the at
least one side rail. In addition, the first and second support members
may be formed from a material that has a lower coefficient of thermal
expansion than the material used to form the first and second guide
blocks.

Claims:

1. A fixture assembly for securing at least one side rail to a shroud
tile of a gas turbine, the fixture assembly comprising: a first support
member, the first support member having an upper portion, a lower portion
and a middle portion extending between the upper and lower portions; a
second support member spaced apart from the first support member, the
second support member having an upper portion, a lower portion and a
middle portion extending between the upper and lower portions; a first
guide block extending between the upper portion of the first support
member and the upper portion of the second support member; and a second
guide block extending between the lower portion of the first support
member first and the lower portion of the second support member, wherein
the first and second guide blocks are formed from a material that has the
same or a similar coefficient of thermal expansion as the material used
to form at least one of the shroud tile and the at least one side rail
and the first and second support members are formed from a material that
has a lower coefficient of thermal expansion than the material used to
form the first and second guide blocks.

2. The fixture assembly of claim 1, wherein the middle portion of the
first support member or the second support member defines an angled
surface configured to support a corresponding angled projection of at
least one of the shroud tile and the at least one side rail.

3. The fixture assembly of claim 1, wherein the middle portion of the
first support member or the second support member is configured to
support an elongated lip of at least one of the shroud tile and the at
least one side rail.

4. The fixture assembly of claim 1, wherein the first and second guide
blocks each extend between a first end and a second end, the first end of
each of the first and second guide blocks being configured to overlap the
first support member and the second end of each of the first and second
guide block being configured to overlap the second support member.

5. The fixture assembly of claim 4, wherein the second end of each of the
first and second guide blocks defines an angled surface generally
corresponding to an angled surface defined by the upper and lower
portions of the second support member.

6. The fixture assembly of claim 4, wherein the first end of each of the
first and second guide blocks defines a stepped surface configured to be
supported by the upper and lower portions of the first support member.

7. The fixture assembly of claim 1, wherein the first and second support
members each include at least one projection and the first and second
guide blocks each define at least one slot, the at least one projection
being configured to be received within at least one slot when the first
and second support members and the first and second guide blocks are
assembled together.

8. The fixture assembly of claim 7, wherein the at least one projection
comprises a projection extending from the upper portion of each of the
first and second support members and a projection extending from the
lower portion of each of the first and second support members.

9. The fixture assembly of claim 7, wherein the at least one slot
includes a protuberance and the at least one projection defines a recess,
the protuberance being configured to be received within the recess when
the at least one projection is received within the at least one slot.

10. The fixture assembly of claim 1, wherein the first and second support
members and the first and second guide blocks, when assembled together,
form a generally rectangular frame configured such that ends of the
shroud tile and the at least one side rail are supported by the first and
second support members when the shroud tile and the at least one side
rail are positioned between the first and second guide blocks.

11. A fixture assembly for securing at least one side rail to a shroud
tile of a gas turbine, the fixture assembly comprising: a first support
member, the first support member having an upper portion, a lower portion
and a middle portion extending between the upper and lower portions; a
second support member spaced apart from the first support member, the
second support member having an upper portion, a lower portion and a
middle portion extending between the upper and lower portions; a first
guide block extending between the upper portion of the first support
member and the upper portion of the second support member; and a second
guide block extending between the lower portion of the first support
member first and the lower portion of the second support member, wherein
the first and second support members and the first and second guide
blocks, when assembled, form a frame configured such that ends of the
shroud tile and the at least one side rail are supported by the first and
second support members when the shroud tile and the at least one side
rail are positioned between the first and second guide blocks.

12. The fixture assembly of claim 11, wherein the first and second guide
blocks are formed from a material that has the same or a similar
coefficient of thermal expansion as the material used to form at least
one of the shroud tile and the at least one side rail and the first and
second support members are formed from a material that has a lower
coefficient of thermal expansion than the material used to form the first
and second guide blocks.

13. The fixture assembly of claim 11, wherein the middle portion of the
first support member or the second support member defines an angled
surface configured to support a corresponding angled projection of at
least one of the shroud tile and the at least one side rail.

14. The fixture assembly of claim 11, wherein the middle portion of the
first support member or the second support member is configured to
support an elongated lip of at least one of the shroud tile and the at
least one side rail.

15. The fixture assembly of claim 11, wherein the first and second guide
blocks each extend between a first end and a second end, the first end of
each of the first and second guide blocks being configured to overlap the
first support member and the second end of each of the first and second
guide block being configured to overlap the second support member.

16. The fixture assembly of claim 15, wherein the second end of each of
the first and second guide blocks defines an angled surface generally
corresponding to an angled surface defined by the upper and lower
portions of the second support member.

17. The fixture assembly of claim 15, wherein the first end of each of
the first and second guide blocks defines a stepped surface configured to
be supported by the upper and lower portions of the first support member.

18. The fixture assembly of claim 11, wherein the first and second
support members each include at least one projection and the first and
second guide blocks each define at least one slot, the at least one
projection being configured to be received within at least one slot when
the first and second support members and the first and second guide
blocks are assembled together.

19. The fixture assembly of claim 18, wherein the at least one projection
comprises a projection extending from the upper portion of each of the
first and second support members and a projection extending from the
lower portion of each of the first and second support members.

20. The fixture assembly of claim 18, wherein the at least one slot
includes a protuberance and the at least one projection defines a recess,
the protuberance being configured to be received within the recess when
the at least one projection is received within the at least one slot.

Description:

FIELD OF THE INVENTION

[0001] The present subject matter relates generally to gas turbines and,
more particularly, to a fixture assembly for repairing a shroud tile of a
gas turbine.

BACKGROUND OF THE INVENTION

[0002] Gas turbines typically include a compressor section, a combustion
section, and a turbine section. The compressor section pressurizes air
flowing into the turbine. The pressurized air discharged from the
compressor section flows into the combustion section, which is generally
characterized by a plurality of combustors disposed in an annular array
about the axis of the engine. Air entering each combustor is mixed with
fuel and combusted. Hot gases of combustion flow from the combustion
liner through a transition piece to the turbine section to drive the
turbine and generate power. The turbine section typically includes a
turbine rotor having a plurality of rotor disks and a plurality of
turbine buckets extending radially outwardly from and being coupled to
each rotor disk for rotation therewith. The turbine buckets are generally
designed to capture and convert the kinetic energy of the hot gases of
combustion flowing through the turbine section into usable rotational
energy.

[0003] The turbine section also includes a substantially cylindrical
turbine casing configured to contain the hot gases of combustion. The
turbine casing typically supports a turbine shroud designed to encase or
shroud the rotating components of the turbine rotor. As is generally
understood, the turbine shroud may be formed from a plurality of shroud
sections or tiles that, when installed around the inner circumference of
the turbine casing, abut one another so as generally define a cylindrical
shape surrounding the turbine rotor and forming the outer perimeter of
the hot gas path of the turbine section. As such, the shroud tiles
generally serve as a heat shield for the turbine casing.

[0004] Due to constant exposure with the hot gases of combustion flowing
through the turbine section, the shroud tiles of the turbine shroud must
often be repaired and/or replaced due to oxidation and/or other damage.
For instance, seals, such as cloth seals, typically extend between seal
slots defined in the sides of adjacent shroud tiles to seal the gap
between such shroud tiles. Over time, the seals may fail leading to hot
gas ingestion between adjacent shroud tiles. As such, the sides of each
shroud tile may often be subject to heavy oxidation, particularly within
the seal slots. To repair such damaged shroud tiles, conventional repair
methods typically involve adding material using a welding and/or brazing
process to build up the damaged side surfaces of the shroud tiles. Once
the side surfaces are built back up with the added material, the surfaces
must then be ground down to establish the proper dimensions of the shroud
tile and new seal slots must be machined into the surfaces. As such, this
repair method is very time and labor intensive, thereby making it very
costly to perform.

[0005] In addition, due to the volume of braze and/or weld material that
must be used during the performance of the conventional repair method,
the shroud tiles must be positioned upright (i.e., with one side of the
shroud tile facing up) to build up the added material along the side of
the shroud tile. Accordingly, each shroud tile may only be repaired one
side at a time, further increasing the amount of time required to repair
each shroud tile. As such, it is often the case that, when both sides of
shroud tile need to be repaired, the damaged shroud tile may simply be
scrapped to avoid the excessive time and costs needed for completely
repairing the shroud tile.

[0006] Accordingly, a new fixture assembly that increases the efficiency
and reduces the cost of repairing damaged shroud tiles would be welcomed
in the technology.

BRIEF DESCRIPTION OF THE INVENTION

[0007] Aspects and advantages of the invention will be set forth in part
in the following description, or may be obvious from the description, or
may be learned through practice of the invention.

[0008] In one aspect, the present subject matter is directed to a fixture
assembly for securing at least one side rail to a shroud tile of a gas
turbine. The fixture assembly may include a first support member, a
second support member, a first guide block and a second guide block. The
first and second guide blocks may be formed from a material that has the
same or a similar coefficient of thermal expansion as the material used
to form at least one of the shroud tile and the at least one side rail.
In addition, the first and second support members may be formed from a
material that has a lower coefficient of thermal expansion than the
material used to form the first and second guide blocks.

[0009] In another aspect, the present subject matter is directed to a
fixture assembly for securing at least one side rail to a shroud tile of
a gas turbine. The fixture assembly may include a first support member, a
second support member, a first guide block and a second guide block. The
first and second support members and the first and second guide blocks,
when assembled, may form a frame configured such that ends of the shroud
tile and the at least one side rail are supported by the first and second
support members when the shroud tile and the at least one side rail are
positioned between the first and second guide blocks.

[0010] These and other features, aspects and advantages of the present
invention will become better understood with reference to the following
description and appended claims. The accompanying drawings, which are
incorporated in and constitute a part of this specification, illustrate
embodiments of the invention and, together with the description, serve to
explain the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] A full and enabling disclosure of the present invention, including
the best mode thereof, directed to one of ordinary skill in the art, is
set forth in the specification, which makes reference to the appended
figures, in which:

[0012] FIG. 1 illustrates one embodiment of a conventional turbine casing
and turbine shroud of a gas turbine, with the turbine shroud being formed
from a plurality of shroud tiles (one of which is shown);

[0014] FIG. 3 illustrates a flow diagram of one embodiment of a method for
repairing a shroud tile of a gas turbine;

[0015] FIG. 4 illustrates a top view of one embodiment of a shroud tile in
the process of being repaired in accordance with the disclosed method;

[0016] FIG. 5 illustrates a perspective view of one embodiment of a shroud
tile assembly that may be formed after a shroud tile is repaired in
accordance with the disclosed method;

[0017] FIG. 6 illustrates a perspective view of embodiment of a fixture
assembly that may be utilized to repair shroud tiles;

[0018] FIG. 7 illustrates a top view of the fixture assembly shown in FIG.
6, particularly illustrating a shroud tile and side rails positioned
within the fixture assembly;

[0019] FIG. 8 illustrates a cross-sectional view of the fixture assembly
shown in FIG. 7 taken about line 8-8; and

[0020] FIG. 9 illustrates a cross-sectional view of the fixture assembly
shown in FIG. 7 taken about line 9-9.

DETAILED DESCRIPTION OF THE INVENTION

[0021] Reference now will be made in detail to embodiments of the
invention, one or more examples of which are illustrated in the drawings.
Each example is provided by way of explanation of the invention, not
limitation of the invention. In fact, it will be apparent to those
skilled in the art that various modifications and variations can be made
in the present invention without departing from the scope or spirit of
the invention. For instance, features illustrated or described as part of
one embodiment can be used with another embodiment to yield a still
further embodiment. Thus, it is intended that the present invention
covers such modifications and variations as come within the scope of the
appended claims and their equivalents.

[0022] In general, the present subject matter is directed to a method for
repairing a shroud tile of a gas turbine. Specifically, in several
embodiments, the method may include removing damaged portions of the
shroud tile along its sides and securing replacement side rails to the
shroud tile in place of the removed portions. By utilizing such a repair
method, shroud tiles may be quickly and efficiently repaired. In
addition, the resulting shroud tile assembly (including the original
shroud tile and the replacement side rails) may be within dimensional
tolerances without the need for additional machining, thereby reducing
manufacturing and labor costs.

[0023] Moreover, the present subject matter is also directed to a fixture
assembly that may be utilized in repairing a damaged shroud tile, such as
by using the fixture assembly in performing the disclosed method. In
several embodiments, the fixture assembly may be configured as a braze
fixture to facilitate brazing the replacement side rails onto the sides
of a shroud tile. For instance, the components of the fixture assembly
may be formed from dissimilar materials having differing coefficients of
thermal expansion. Thus, during the brazing thermal cycle when the shroud
tile and replacement side rails are heated within the fixture assembly,
the components of the fixture assembly may expand at differing rates,
thereby applying a compressive force against the shroud tile and side
rails. Application of such a compressive force may generally improve
formation of the braze joint defined between the shroud tile and the side
rails and may also assist in controlling the final dimension of the
resulting shroud tile assembly. Moreover, the fixture assembly may also
allow for both sides of a damaged shroud tile to be repaired at the same
time, thereby reducing manufacturing and labor costs.

[0024] Referring now to the drawings, FIGS. 1 and 2 illustrate
cross-sectional and perspective views of one embodiment of a conventional
shroud tile 10. In particular, FIG. 1 illustrates a cross-sectional view
of one embodiment of a portion of a turbine casing 12 and a turbine
shroud 14 of a gas turbine, with the turbine shroud 14 being formed from
a plurality of shroud tiles 10 (one of which is shown). Additionally,
FIG. 2 illustrates a perspective view of the shroud tile 10 shown in FIG.
1.

[0025] As indicated above, the turbine shroud 14 of gas turbine may be
formed from a plurality of shroud tiles 10 configured to be supported
around the inner circumference of the turbine casing 12 so that an inner
surface 16 of the shroud tiles 10 may be disposed adjacent to the tips 18
of the rotating buckets 20 of the turbine rotor (not shown). Thus, in
several embodiments, the turbine casing 12 and shroud tiles 10 may define
corresponding mating features such that the shroud tiles 10 may be
installed around the inner circumference of the turbine casing 12. For
instance, as shown in the illustrated embodiment, each shroud tile 10 may
extend axially between a first end 22 and a second end 24, with each end
22, 24 defining a slot or channel 26, 28 configured to be supported by
and/or engaged with a corresponding hooked projection 30, 32 of the
turbine casing 12. Specifically, as shown in FIG. 1, the first end 22 of
each shroud tile 10 may define a first channel 26 configured to receive
and/or be engaged with a first hooked projection 30 extending from the
turbine casing 12. Similarly, the second end 24 of each shroud tile 10
may define a second channel 28 configured to receive and/or be engaged
with a second hooked projection 32 extending from the turbine casing 12.
However, it should be appreciated that, in alternative embodiments, the
turbine casing 12 and shroud tiles 10 may generally define any other
suitable mating features that permit the shroud tiles 10 to be installed
and/or supported around the inner circumference of the turbine casing 12.

[0026] Additionally, in one embodiment, one or more of the walls defining
the channels 26, 28 of each shroud tile 10 may be elongated. For example,
as shown in FIG. 1, the inner wall of the first channel 26 may be
elongated so as to define a lip 34 that extends axially beyond the
opposing wall of the first channel 26. Similarly, the inner wall of the
second channel 28 may be elongated and may define an angled or curved
projection 36 that extends axially beyond the opposing wall of the second
channel 28. As shown in FIG. 1, in one embodiment, the angle or curvature
of the projection 36 may be configured to generally correspond to the
angle or curvature of an inner surface 38 of the turbine casing 12 at
and/or adjacent to the second hooked projection 32.

[0027] Moreover, as particularly shown in FIG. 2, each shroud tile 10 may
include a first side 40 and a second side 42 extending axially between
its first and second ends 22, 24. In general, the sides 40, 42 of each
shroud tile 10 may be configured to be sealed against the sides 40, 42 of
adjacent shroud tiles 10 when the shroud tiles 10 are installed around
the inner circumference of the turbine casing 12. Thus, in several
embodiments, a seal slot 44 may be defined in each side 40, 42 of the
shroud tiles 10 to allow a corresponding seal (e.g., a cloth seal) to be
installed between the sides 40, 42 of adjacent shroud tiles 10. However,
as described above, the seals installed between shroud tiles 10 may often
fail, resulting in the sides 40, 42 of the shroud tiles 10 being exposed
to the hot gases flowing through the turbine section of the gas turbine.
Such exposure can lead to heavy oxidation and/or other damage to the
sides 40, 42 of the shroud tiles 10.

[0028] Referring now to FIG. 3, there is illustrated a flow diagram of one
embodiment of a method 100 for repairing a shroud tile of a gas turbine.
As shown, the method 100 generally includes removing a portion of the
shroud tile along at least one of the first side and the second side of
the shroud tile 102 and securing at least one side rail to the shroud
tile in place of the removed portion of the shroud tile 104.
Specifically, in several embodiments, when damage has occurred to one or
both of the sides 40, 42 of a shroud tile 10, the damaged portion(s) may
be removed and replaced with a side rail 202, 204 (FIGS. 4 and 5)
configured to be secured to the first and/or second side 40, 42 of the
shroud tile 10.

[0029] For example, FIGS. 4 and 5 illustrate views of a shroud tile 10
that is being and has been repaired in accordance with the disclosed
method 100, respectively. In particular, FIG. 4 illustrates a top view of
a shroud tile 10 prior to replacement side rails 202, 204 being secured
to the sides 40, 42 of the shroud tile 10. Additionally, FIG. 5
illustrates a perspective view of a repaired shroud tile assembly 200,
particularly illustrating the shroud tile 10 after the replacement side
rails 202, 204 have been secured thereon.

[0030] As particularly shown in FIG. 4, when damage has occurred to the
first side 40 of a shroud tile 10, a first portion 206 of the shroud tile
10 (indicated by dashed lines) corresponding to the damaged portion of
the shroud tile 10 along the first side 40 may be removed (e.g., by
removing a strip of material along the first side 40 that extends between
the first and second ends 22, 24 of the shroud tile 10). Similarly, when
damage has occurred to the second side 42 of a shroud tile 10, a second
portion 208 of the shroud tile 10 (indicated by dashed lines)
corresponding to the damaged portion of the shroud tile 10 along the
second side 42 may be removed (e.g., by removing a strip of material
along the second side 42 that extends between the first and second ends
22, 24 of the shroud tile 10). It should be appreciated that the damaged
portions 206, 208 of the shroud tile 10 may be removed using any suitable
manufacturing/machining process known in the art. For example, in one
embodiment, the damaged portions 206, 208 may be removed from the shroud
tile 10 using a waterjet machining process. In other embodiments, the
damaged portions 206, 208 may be removed using a grinding process, an
electrical discharge machining (EDM) process, a laser cutting process or
any other suitable manufacturing/machining process capable of removing
the damaged portions 206, 208 from the sides 40, 42 of the shroud tile
10.

[0031] Referring still to FIGS. 4 and 5, upon removing the damaged
portions 206, 208 of the shroud tile 10, one or more replacement side
rails 202, 204 may then be secured to the shroud tile 10. For example, as
shown in the illustrated embodiment, a first side rail 202 may be
configured to be secured along the first side 40 of the shroud tile 10 in
order to replace the removed, first portion 206 of the shroud tile 10.
Similarly, a second side rail 204 may be configured to be secured along
the second side 42 of the shroud tile 10 in order to replace the removed,
second portion 208 of the shroud tile 10. However, in instances in which
damage has only occurred to one of the sides 40, 42 of the shroud tile
10, it should be appreciated that only a portion of the shroud tile 10
along the damaged side may need to be removed and replaced with a
corresponding side rail 202, 204.

[0032] It should also be appreciated that the side rails 202, 204 may be
secured to the sides 40, 42 of each shroud tile 10 using any suitable
attachment method and/or means known in the art. For example, in one
embodiment, the side rails 202, 204 may be secured to the sides 40, 42 of
each shroud tile 10 using a brazing process, such as a vacuum brazing
process or a furnace brazing process. In another embodiment, the side
rails 202, 204 may be secured to the sides 40, 42 of each shroud tile 10
using a welding process. In further embodiments, the side rails 202, 204
may be secured to each shroud tile 10 using suitable mechanical fasteners
(e.g., pins, bolts, rivets and/or the like) and/or using any other
suitable attachment method and/or means.

[0033] In addition, it should be appreciated that the dimensions and/or
shape of the replacement side rails 202, 204 may generally correspond to
the dimensions and/or shape of the portions 206, 208 of the shroud tile
10 being removed. For example, as shown FIG. 4, the side rails 202, 204
may define a width 210 generally corresponding to a width 212 of the
removed portions 206, 208 of the shroud tile 10. Similarly, the side
rails 202, 204 may be configured to define the same or a similar
cross-sectional profile as the shroud tile 10. For example, as shown in
FIG. 5, each side rail 202, 204 may be configured to extend axially along
the entire length of the shroud tile 10 (i.e., between the first and
second ends 22, 24 of the shroud tile 10) and may also define the same
mating features as the shroud tile 10, such as by defining channels 214,
216 corresponding to the channels 26, 28 defined at the ends 22, 24 of
the shroud tile 10, by including an elongated lip 218 corresponding to
the lip 34 formed at the first end 22 of the shroud tile 10 and/or by
including an elongated projection 220 corresponding to the projection 36
formed at the second end 24 of the shroud tile 10.

[0034] Additionally, as shown in FIG. 5, a seal slot 222 may be formed in
each side rail 202, 204. For example, in several embodiments, the seal
slot 222 may be formed using a waterjet machining process, a laser
cutting process, an EDM process, a casting process and/or any other
suitable machining/manufacturing process. As indicated above, the seal
slots 222 may be configured to receive corresponding seals (not shown)
for sealing the gap defined between adjacent shroud tiles 10 when the
shroud tiles 10 are installed around the inner circumference of the
turbine casing 12. It should be appreciated that, in one embodiment, the
seal slots 222 may be pre-formed in the side rails 202, 204 (i.e., formed
before the side rails 202, 204 are secured to the sides 40, 42 of the
shroud tile 10). However, in another embodiment, the seal slots 222 may
be formed in the side rails 202, 204 after the side rails 202, 204 are
secured to the sides 40, 42 of the shroud tile 10.

[0035] Moreover, it should be appreciated that the side rails 202, 204 may
generally be formed from any suitable material. For example, in several
embodiments, the side rails 202, 204 may be formed from the same material
as the material used to form the shroud tiles 10 (e.g., Inconel or any
other suitable material). Alternatively, the side rails 202, 204 may be
formed from a different material than the material used to form the
shroud tiles 10. For instance, it may be desirable to form the side rails
202, 204 from a material that has better mechanical properties (e.g.,
increased oxidization resistance) than the material used to form the
shroud tiles 10.

[0036] Referring now to FIGS. 6-9, one embodiment of a fixture assembly
300 that may be utilized to both locate a shroud tile 10 and its
corresponding side rails 202, 204 relative to another and facilitate
securing such side rails 202, 204 to the shroud tile 10 is illustrated in
accordance with aspects of the present subject matter. In particular,
FIG. 6 illustrates a perspective view of the fixture assembly 300. FIG. 7
illustrates a top view of the fixture assembly 300 having a shroud tile
10 and first and second side rails 202, 204 installed therein. FIG. 8
illustrates a cross-sectional view of the fixture assembly 300 shown in
FIG. 7 taken about line 8-8. Additionally, FIG. 9 illustrates a
cross-sectional view of the fixture assembly 300 shown in FIG. 7 taken
about line 9-9.

[0037] As shown, in several embodiments, the fixture assembly 300 may be
configured as four-piece assembly and may include a first support member
302, a second support member 304, a first guide block 306 and a second
guide block 308. In general, the support members 302, 304 and guide
blocks 306, 308 may be configured to be assembled together to form a
rectangular frame for receiving both a shroud tile 10 to be repaired and
its replacement side rail(s) 202, 204. For example, as shown in FIGS. 6
and 7, the first and second support members 302, 304 may be configured to
be spaced apart from one another so as to generally define two parallel
sides of the rectangular frame. Similarly, the first and second guide
blocks 306, 308 may be spaced apart from one another and may be
configured to extend transversely between the first and second support
members 302, 304 so as to define the remaining sides of the rectangular
frame.

[0038] In general, the first and second support members 302, 304 may each
include an upper portion 310, a lower portion 312 and a middle portion
314 extending between the upper and lower portions 310, 312. The upper
and lower portions 310, 312 of each support member 302, 304 may generally
be configured to support and/or be engaged with at least a portion of the
first and second guide blocks 306, 308. For example, as shown in the
illustrated embodiment, the first guide block 306 may be configured to
extend between the upper portions 310 of the support members 302, 304,
with a first end 316 of the first guide block 306 overlapping and being
supported by the upper portion 310 of the first support member 302 and a
second end 318 of the first guide block 306 overlapping and being
supported by the upper portion 310 of the second support member 203.
Similarly, the second guide block 308 may be configured to extend between
the lower portions 312 of the support members 302, 304, with a first end
316 of the second guide block 308 overlapping and being supported by the
lower portion 312 of the first support member 302 and a second end 318 of
the second guide block 308 overlapping and being supported by the lower
portion 312 of the second support member 304.

[0039] Additionally, in several embodiments, the support members 302, 304
and guide blocks 306, 308 may include corresponding surface/overlapping
features at the locations at which the guide blocks 306, 308 overlap the
support members 302, 304. For example, as particularly shown in FIG. 8,
in one embodiment, the second end 316 of each guide block 306, 308 may
define an angled surface 320 configured to overlap and/or engage a
corresponding angled surface 322 defined by the upper and lower portions
310, 312 of the second support member 304. In addition to such angled
features or as an alternative thereto, the support members 302, 304
and/or guide blocks 306, 308 may include any other suitable
surface/overlapping features. For example, a shown in FIG. 8, in one
embodiment, the first end 316 of each guide block 306, 308 may define a
stepped surface 324 configured to be engaged against and/or supported by
the upper and lower portions 310, 312 of the first support member 302.

[0040] Moreover, the middle portion 314 of each support member 302, 304
may generally be configured to support both the shroud tile 10 to be
repaired and its corresponding side rails 202, 204 within the fixture
assembly 300. In particular, when the shroud tile 10 and side rails 202,
204 are positioned within the fixture assembly 300 between the first and
second guide blocks 306, 308, the ends of the shroud tile 10 and side
rails 202, 204 may generally overlap and/or be supported by the middle
portions 314 of the support members 302, 304. For example, as shown in
FIG. 9, the lip 34 defined at the first end 22 of the shroud tile 10 and
the corresponding lip 218 (FIG. 5) of the side rails 202, 204 may be
configured to overlap and/or engage the middle portion 314 of the first
support member 302. Similarly, the angled and/or curved projection 36
defined at the second end 24 of the shroud tile 10 and the corresponding
projection 220 of the side rails 202, 204 may be configured to overlap
and/or engage a corresponding angled surface 326 defined by the middle
portion 314 of the second support member 304. Accordingly, the shroud
tile 10 and side rails 202, 204 may be suspended and/or otherwise
supported between the first and second support members 302, 304 when such
components are installed within the fixture assembly 300.

[0041] It should be appreciated that the support members 302, 304 and
guide blocks 306, 308 may also include alignment and/or engagement
features configured such that the support members 302, 304 and guide
blocks 306, 308 are properly aligned within one another and/or properly
engaged when such components are assembled together to form the fixture
assembly 300. For example, as shown in FIGS. 6-8, in several embodiments,
the support members 302, 304 may have a "C-shape" and may include
projections 328 configured to be received within corresponding slots 330
defined in the guide blocks 306, 308. As such, when the first and second
guide blocks 306, 308 are positioned over the support members 302, 304,
the projections 328 may be slidably received within the slots 330,
thereby ensuring proper alignment and/or engagement of the guide blocks
306, 306 with the support members 302, 304. In addition, the support
members 302, 304 and guide blocks 306, 308 may also include further
alignment and/or engagement features. For instance, as particularly shown
in FIGS. 6 and 7, each slot 330 defined by the guide blocks 306, 308 may
include a protuberance 332 extending therein that is configured to be
received within a corresponding recess 334 defined in each projection 328
of the support members 302, 304. It should be appreciated that, in
alternative embodiments, the support members 302, 304 and guide blocks
306, 308 may include any other suitable alignment and/or engagement
features.

[0042] Referring still to FIGS. 6-8, in several embodiments, the fixture
assembly 300 may be utilized in performing embodiments of the disclosed
method 100. In particular, the fixture assembly may be designed to
simplify and/or enhance the efficiency and/or accuracy of securing the
side rails 202, 204 onto the sides 40, 42 of a shroud tile 10. For
example, by configuring the fixture assembly 300 as described above, the
shroud tile 10 and the side rails 202, 204 may be properly positioned
relative to one another when such components are installed within the
fixture assembly 300. Specifically, as shown in FIG. 7, a width 336
defined between the guide blocks 306, 308 may generally correspond to the
combined width of the shroud block 10 and side rails 202, 204. As such,
when the shroud block 10 and side rails 202, 204 are installed within the
fixture assembly 300, the shroud block 10 and side rails 202, 204 may be
aligned relative to one another in the side-to-side direction (indicated
by arrow 338). Additionally, as shown in FIG. 9, the mating features of
both the shroud tile 10 and the side rails 202, 204 (e.g., the lips 34,
218 and projections 36, 220) may be configured to engage/overlap/contact
the support members 302, 304 at the same locations, thereby positioning
the shroud tile 10 and the side rails 202, 204 relative to one another in
the longitudinal direction (indicated by arrow 320). Such precise
alignment of the shroud tile 10 and the side rails 202, 24 may be
particularly advantageous when such components are being secured together
using a brazing and/or welding process.

[0043] Additionally, in embodiments in which the side rails 202, 204 are
secured to the sides 40, 42 of a shroud tile 10 using a brazing process,
the fixture assembly 300 may also be configured to apply a compressive
load against the side rails 202, 204 (i.e., in the side-to-side direction
338), thereby ensuring that the width of the resulting shroud tile
assembly 200 is to the proper dimension. Specifically, in several
embodiments, the materials used to form the support members 302, 304 and
guide blocks 306, 308 may be selected such that the fixture assembly 300
restricts thermal expansion of the shroud tile 10 and side rails 202, 204
in the side-to-side direction 338 while heating such components within
the fixture assembly 300 during the brazing thermal cycle. For instance,
in one embodiment, the guide blocks 306, 308 may be formed from a
material (e.g., Inconel or any other suitable material) that has the same
or a similar coefficient of thermal expansion as the material(s) used to
form the shroud tile 10 and the side rails 202, 204. In addition, the
support members 302, 304 may be formed from a material (e.g., TZM
Molybdenum or any other suitable material) that has a lower coefficient
of the thermal expansion than the material(s) used to form the guide
blocks 306, 308, shroud tile 10 and side rails 202, 204. As such, when
the fixture assembly 300, shroud tile 10 and side rails 202, 204 are
heated during the brazing process (e.g., in a furnace or vacuum chamber),
the guide blocks 306, 308, shroud tile 10 and side rails 202, 204 may
expand together in the longitudinal direction 340 (e.g., by pushing the
support members 302, 304 away from one another). However, due to the low
coefficient of thermal expansion of the support members 302, 304, the
outward thermal expansion of the guide blocks 306, 308, shroud tile 10
and side rails 202, 204 may be restricted in the side-to-side direction
338, thereby squeezing the shroud tile 10 and side rails 202, 204
together within the fixture assembly 300. Thus, by controlling the
dimensions of the shroud tile 10, the side rails 202, 204 and the
components of the fixture assembly 300, the resulting shroud tile
assembly 200 may be to the proper dimensions without the necessity of
further machining and/or processing.

[0044] It should be appreciated that, although the embodiments illustrated
herein show two side rails 202, 204 being installed within the fixture
assembly 300, the fixture assembly 300 may also be utilized to facilitate
securing a single side rail to a shroud tile 10, such as in instances
when only one of the sides 40, 42 of the shroud tile 10 has been oxidized
and/or otherwise damaged and needs to be repaired.

[0045] This written description uses examples to disclose the invention,
including the best mode, and also to enable any person skilled in the art
to practice the invention, including making and using any devices or
systems and performing any incorporated methods. The patentable scope of
the invention is defined by the claims, and may include other examples
that occur to those skilled in the art. Such other examples are intended
to be within the scope of the claims if they include structural elements
that do not differ from the literal language of the claims, or if they
include equivalent structural elements with insubstantial differences
from the literal languages of the claims.

Patent applications by Mark Lawrence Hunt, Simpsonville, SC US

Patent applications by Steven Charles Woods, Easley, SC US

Patent applications by GENERAL ELECTRIC COMPANY

Patent applications in class Having mounting or supporting structure

Patent applications in all subclasses Having mounting or supporting structure